The present invention relates to light diminishing shields in general. More specifically to a shield removably attached over a self contained breathing apparatus face plate lens visually simulating smoke intensity for firefighting training.
In order to enter buildings and structures that are on fire and filled with smoke, firefighters typically utilize a self contained breathing apparatus along with protective clothing. Since high visibility is the goal of the apparatus manufacturer""s considerable effort has been accomplished to make the mask face plate as large as possible and configured for maximum visual perception. As such, limiting vision has not been developed to any extent at the present time.
The prior art listed below did not disclose patents that possess any of the novelty of the instant invention; however the following U.S. patents are considered related relative to the self contained breathing apparatus mask:
Backlund in U.S. Pat. No. 4,057,057 teaches a breathing mask having spectacles and a method of attaching them to either a half mask or an inner mask.
U.S. Pat. No. 4,069,516 issued to Watkins Jr. is for a resilient flexible sealing element conformable to the face of a wearer supported by a mask body. The sealing element extends completely around the open side of the mask body with a hinge web having a bead extending along the opposite sides and across the top of the mask for controlled buckling of the web in a manner mechanically loading the face engaging sealing element.
Urso in U.S. Pat. No. 5,069,205 teaches a quick donning head harness assembly for a respirator face mask using a rigid face piece and a flexible face seal. The head harness includes a cap with a lower strap casing and an upper strap casing. Rings connect to the upper corners of the face piece and an upper adjustable strap has right and left temple portions passing through the rings.
U.S. Pat. No. 5,080,092 issued to Tenna describes a protective mask that has a face shield covering the user""s face formed of a rigid transparent material rimmed by a bellows seal. The seal provides the necessary tightness with comfort allowing continuous use of the mask even over an extended length of time.
Lewis et al in U.S. Pat. No. 6,062,222 disclose a face mask for a self contained breathing apparatus that has two pairs of straps fixed to the frame and a net head piece. The straps at the top of the head piece are fixed and the bottom straps are adjustable. A nose cup includes ribs that receive legs of a mounting member for eyeglasses. The mounting member moves relevant to the user""s eyes.
Joyce in U.S. Pat. No. 6,347,401 teaches a thin protective sheet for covering a face plate on an air mask. This invention may comprise a substantially rectangular thin sheet of plastic having two circular cut outs and square cut outs with an edge having a semi-circular shape. Other embodiments may have a series of curves or oval shapes to fit around the mask protecting the mask from scratches, nicks, scrapes or any other damage from use.
Previously, self contained breathing apparatus, described hereafter as SCBA, have been used in conjunction with smoke filled rooms for training firefighters. Training using the actual SCBA in environments where smoke partially or almost totally engulfs the firefighter is extremely beneficial as it acquaints the trainee with the peripheral visual limitations of the SCBA mask and the murky surroundings of smoke. While this type of training is ideal, the cost to fill a room with smoke is expensive as a specialized structure and smoke generating equipment is required, further it takes time to ignite material in the generator and wait until sufficient smoke is created before the training can begin.
It is therefore a primary object of the invention to simulate the actual visual impairment of a selected density of smoke in a non-specialized convenient environment. This object is realized by the use of a shield that is translucent, limiting light penetration, and is configured to fit either on the outside or inside of the self contained breathing apparatus face plate lens. The shield slightly overlaps the face plate lens preventing any leakage of light and is held in place with pressure sensitive tape or the like. It may be clearly seen that this system of training may be used anytime and anywhere enhancing safety aspects of the trainees.
An important object of the invention is that the instructor may now clearly view the actions of the trainees and even video tape the session for de-briefing at a later time where the trainee may actually see how he or she reacted with limited vision. This approach permits trainers to direct each session much more effectively.
Another object of the invention eliminates the environmental hazards related to smoke making machines and from discharging the smoke into the atmosphere.
Still another object of the invention permits the instruction to be accomplished with a specifically selected smoke density as it has been found that three totally different shades of translucent material used in the construction of the shield duplicates a light smoke density for limited visibility, a medium smoke density for intermediate visibility and a dark smoke density for total smoke engulfment. With a smoke generating machine it is difficult to control the density and therefore training is subject to variable situations.
Yet another object of the invention is the cost savings realized by the training agency as the training budget may be used in other areas enhancing the overall training effort. Since this type of training may be required in other areas than professional firefighting, the invention is of great value since an inexpensive shield over the face plate lens of the SCBA mask may replicate and eliminate the need of a separate chamber filled with smoke.
A further object of the invention is its simplicity in use as the shield is held in place with pressure sensitive tape which is easy to install and intuitively obvious in its application and may be reused a number of times.
A final object of the invention is its adaptability to be used in different manufacturer""s equipment. Each self SCBA maker makes a different style of mask; therefore the invention may be specifically configured to fit every style as only a different production tool is required to duplicate each shape. While there are a number of different manufacturers the most commonly used equipment by firefighting agencies are Scott, Survivair, MSA and ISI.